This invention relates to wire guided material handling vehicles, and particularly the control of such vehicles when the signal from the signal carrying wire is lost.
When a wire guided vehicle is in the automatic mode, or when the operator is attempting to engage the automatic guidance system, it is important that the vehicle's speed and relation to the wire be within those limits that will allow the guidance system to position the vehicle quickly and without significant overshoot. There are some circumstances where manual control of the vehicle is preferred over automatic control, especially when initially positioning the vehicle over the wire, since the operator can maneuver the vehicle backwards and forwards, if necessary, to achieve proper position.